摘要
直升机在斜下降飞行时旋翼产生的桨涡干扰(BVI)噪声十分严重,桨距主动控制是降低旋翼BVI噪声的有效手段之一。为摸索其对旋翼BVI噪声的影响规律并阐释其机理,开展了开环桨距主动控制对旋翼BVI噪声的影响研究。建立能够计入开环桨距主动控制的旋翼自由尾迹模型,并结合翼型气动力模型及基于FW-H(Ffowcs Williams-Hawkings)方程的旋翼载荷噪声计算模型,建立旋翼BVI噪声开环主动控制模型。以40%缩比的4桨叶BO-105直升机模型旋翼为算例,在风洞配平状态下开展开环桨距主动控制对旋翼BVI噪声的影响研究。通过分析算例旋翼在不同相位、幅值的桨距主动控制下的BVI噪声声压级、桨盘气动载荷及桨盘迎角分布,总结出开环桨距主动控制影响旋翼BVI噪声的规律,并初步阐释了其机理:适当的桨距主动控制可改善桨盘迎角分布,降低桨涡干扰位置附近的桨叶气动载荷,从而降低BVI噪声。
Blade-vortex interaction （BVI） noise is one of the most annoying and intrusive kinds of noise and becomes dominant during skew descent flight,and open-loop active blade pitch control is one of the effective means to reduce BVI noise.A research on the effect of open-loop active blade pitch control on rotor BVl noise alleviation is carried out to find out the influencing rules and to make clear the mechanism of it.The rotor free wake model which could consider the impact of openloop active blade pitch control is built first,and then open-loop active blade-pitch control on rotor BVI noise alleviation model is established with the rotor aerodynamic model and the rotor loading noise model based on the FW-H （Ffowcs WilliamsHawkings） equation.The research is carried out to investigate the effect of open-loop active blade pitch control on BVI noise level based on a 40-percent geometrically scaled BO-105 helicopter model rotor under wind trim conditions.By analyzing variations of BVI sound pressure level and the distribution of angle of attack on rotor disk when experiencing phase sweep and amplitude sweep control,the influencing rules of active blade pitch control on BVl noise level are summarized,and the mechanism of BVI noise reducing through active blade pitch control is found out：appropriate active blade pitch control could improve the distribution of angle of attack on rotor disc,and then decrease aerodynamic loads where BVI happens,causing the alleviation of BVI noise finally.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2014年第11期2901-2909,共9页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(51375229)
南京航空航天大学青年科学创新基金(NS2013002)~~
关键词
直升机
旋翼
桨涡干扰
噪声
自由尾迹
主动控制
helicopter
rotor
blade-vortex interaction
noise
free wake
active control
